The yam with vegetable sauce looks very tasty. I totally understand your shocked if a dish that is one of your favourites, tasted different that what your are accustomed to. As the saying goes - "one man's meat is another man's poison". This situation is a good depiction of this saying with you depositing the food from your mouth into a serviette. Was he surprised that you did not even swallow it and that you did not want to eat the meal he prepared for you? I hope he was not too upset.
It is nice that you were provided something else to satisfy your worms and your palate. 😀
